This image captured from the website of the Gongju Correctional Institution shows a prison cell. Yonhap

An appellate court sentenced a life prisoner to death on Thursday for beating and killing a prison inmate.

The Daejeon High Court handed down the death penalty to the 28-year-old charged with strangling and kicking a 42-year-old inmate to death in a cell they shared at a prison in Gongju, 125 kilometers south of Seoul, in December of 2021.

A district court had earlier sentenced him to life in prison, but prosecutors appealed and demanded capital punishment, saying sentencing a lifer to another life term is pointless and death penalty is needed to prevent further violence by him and to keep correctional institutions in order.

The man was serving a life sentence for murdering a man in the city of Gyeryong in 2019 and robbing him of nearly 400 grams of gold and a sedan.

"It is questionable whether he has any possibility of reformation, given that he murdered two people in a short period of time and repeatedly used violence against the victim," the Daejeon High Court said.

"It is also questionable what meaning it would have to sentence a man already serving a life sentence to life imprisonment or a lower sentence," it said.

The appellate court also sentenced two other accomplices charged with murder to 12 years and 14 years behind bars, respectively.

Investigations showed the three assaulted the victim by pouring hot water over his head and using clothespins to pinch him. They also forced him not to see a doctor and not to have his family members visit him for fear he could expose their violence.

The victim, initially healthy except for an underlying heart disease, eventually died of bleeding, inflammation and fractured ribs within 20 days of the violence. (Yonhap)